CZ297829B6 - Method and device for forming one-piece flange or rim on the end of a pipe - Google Patents

Abstract

The present invention relates to a method and device for forming a one-piece flange or rim on the end of a steel or sheet metal pipe. The pipe is placed in a flat position on all sides on the inner surface thereof close to the end thereof and is clamped. One part of the pipe protrudes above the clamped section of the tube. The protruding part of the pipe is bent by applying surface pressure against a peripheral section on the inner surface thereof, until a desired outward flectional angle is obtained. The desired flectional angle on all parts of the pipe or a part or section thereof is gradually achieved by rotating the pipe relative to the peripheral section wherein the flexing occurs. There is also disclosed a device for carrying out the above-described method, said device being characterized by a clamping disk (22) with cylindrical circumference surface (48) introducible into the inside of the pipe (12), which is adjustable between a resting setting spaced closely to the inner surface of the pipe (12) and a spread setting with frictional engagement against the inner circumference of the pipe, a drive shaft (24) mounted fixed against rotation relative to the clamping disk (22), a drive motor (146) for rotating the drive shaft (24) against great resistance, and a bending jaw (26, 30) pivotable between a rest position lying against the inner side of the pipe to be bent (10, 18) and a work position representing the finished bent pipe piece (10, 18) with an at least partially cylindrical contact surface (190) for contact with the pipe piece (10, 18), wherein the cylindrical diameter of the contact surface (190) is smaller than or equal to the diameter of the pipe piece to be bent (10, 18) and the cylinder height of the contact surface (190) is greater than the length of the pipe piece.

Description

Method and apparatus for uniformly molding a flange or flange at the end of a sheet metal pipe (57)

In the method for uniformly molding a flange or flange at the end of a sheet metal tube, the tube near its end on its inner side is supported and clamped on all sides, allowing the pipe piece to protrude over the supported and clamped pipe section. At least one axial partial section of the protruding tubular piece is bent by flat pressure against the circumferential section of its inner surface up to the desired bending angle outward from the pipe axis and relative rotation of the tube with respect to the circumferential section in which the entire tubular piece or its the desired bending angle is given to the partial section. The apparatus for carrying out this method comprises a disc (22) with a cylindrical outer surface (48) for insertion into the tube (12), which is adjustable between a parking position at a slight distance from the inner surface of the tube (12) and span. friction, a drive shaft (24) fixed to the clamping disk (22), a drive motor (146) to rotate the drive shaft (24) against high resistance, and a bending jaw (26, 30) with at least partially cylindrical bearing surface (190) to engage a tubular piece (10, 18) that is rotatable between a parking position with abutment on the inside of the bent tubular piece (10, 18) and an operating position corresponding to the finished bent tubular piece (10, 18). The cylindrical diameter of the bearing surface (190) is less than or equal to the diameter of the bent tubular piece (10, 18) and the cylindrical height of the bearing surface (190) is greater than the length of the tubular piece (10, 18).

Method and apparatus for uniformly molding a flange or rim at the end of a sheet metal tube

Technical field

BACKGROUND OF THE INVENTION The present invention relates to a method and apparatus for uniformly molding a flange or flange at the end of a sheet metal tube.

In particular, the invention relates to relatively thin-walled pipes, which means a range of diameters from 100 to 3000 mm and wall thicknesses from 0.5 to 6.0 mm. Such pipes are mainly used for air ducts, fan housings, instruments etc. in air-conditioning, air-conditioning and exhaust systems, but also in transport technology.

BACKGROUND OF THE INVENTION

Various connection techniques are known for the tight and rigid connection of the individual tubular sections. They have a decisive influence on the economy and technical properties of the pipe system. Until now, angular, flat or otherwise shaped flanges have been predominantly used on the end of the tube and attached to the end of the tube, although the advantages are straight, ie. uniformly at the ends of the preformed pipes, the flanges become apparent and there is therefore a need for preformed flanges and flanges.

Essentially, the absence of a method that would allow the desired flange shapes to be formed at the ends of large-volume tubes, at reasonable cost, at a reasonable cost. At present, only radially protruding annular flanges with relatively low stability or radially protruding flat flanges, which are punched for screwing, are molded. The latter are mainly used for fan cabinets.

Single seams can be produced on serration and hemming machines. Later perforated flat flanges are produced by a pressure method. The tubular body is brought to a high orbital speed, which is only possible with very short tubular bodies such as axial fan housings. The pipe end is slid into the negative form of the flat flange.

The push lever, at the end of which the pulley orbits, is now "pushed" and rapidly circulating the pipe end until the material is in a creep state and is brought to a negative form. The "pressure" method is similar to the formation of clay on the potter's wheel. It is also used to mold annular rims into short tubular rings which are then slid onto the tubular ends and fixed there. This latter method is described, for example, in DE-A1-196 32 857.

This known method is not suitable for flanging the flanges directly to the pipe end, since it is almost impossible and also dangerous to bring larger pipes to the necessary peripheral speed. Also, the costs for the different shapes of the various pipes are too high in terms of cost-effective work. First of all, the production of the desired flange shapes, such as conical flanges or the like, is not possible due to the undercuts which occur thereby, since the finished flange could not be removed.

The so-called folding method or rotary folding method is known for the production of cabinets, profile frames or channels with straight edges. In this case, the planar sheet is clamped between the fixed lower arm and the movable upper arm and is bent by means of a rotary bending arm.

A great advantage here is that in the case of rotary bending, the entire sheet section can be raised and folded without extension. Only in the area of the forming edge the sheet material must be in a creep state. All other material remains unchanged. That is why the edge profiles are exactly flat and stress-free without elongation and without special costs. Against this is at the top

All material is calibrated and thus affected by the respective stresses. As a result, the energy costs of rotary bending are considerably lower.

SUMMARY OF THE INVENTION

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method and apparatus for carrying out this method with which it is possible to carry out a uniform molding of complicated flanges and flanges not only on short, but especially on long, tubular pieces, at cost.

The object is achieved by developing a method for uniformly flanging a flange or rim at the end of a sheet metal tube according to the invention, which is to support the tube on its inner side in a versatile manner and clamp on its inner side while leaving it flat and clamped a pipe section extending over the pipe piece that at least one axial partial section of the overlapping pipe piece is bent flatly against a peripheral section of its inner surface up to a desired bending angle outward from the pipe axis and that relative rotation of the pipe relative to the peripheral section bending occurs, the entire bending piece or part thereof is given the desired bending angle.

In order to carry out this method, a device has been developed which comprises a clamping disk with a cylindrical outer surface for insertion into the tube, which is adjustable between a parking position at a slight distance from the inner surface of the tube and a span position with the outer surface with friction further comprising a fixed drive shaft coupled to the clamping disk, a drive motor for rotating the drive shaft against high resistance, and a bending jaw with an at least partially cylindrical bearing surface for abutting the tubular piece rotatably between the parking position abutting the inner side of the bent tubular piece; a cylindrical diameter of the bearing surface is less than or equal to the diameter of the bent tubular piece and the cylindrical height of the bearing surface is greater than the length of the tubular piece.

The method according to the invention is based on exploiting the advantages of the linear rotary bending method also when bending the pipe ends. It is therefore referred to as a rotary rotary bending method.

Of course, the linear rotary bending method cannot be transferred to the circular tubes without modification, since they do not have to produce straight but curved edges and these have yet to be produced with different radii and preferably without changing tools.

The invention accomplishes this by circularly clamping the tubular end from the inside, for example by means of a clamping disc. This clamping disc has a slightly smaller diameter than the inner diameter of the pipe before clamping. After insertion is strutted, ie. its diameter is increased until its outer circumference is stretched on the inside of the tubular wall.

The clamping disk, or other devices used for clamping, can be coupled to a fixed drive axis for rotating the tube. Thus, the rigid clamping of the pipe end is simultaneously used to rotate the pipe, and of course only a substantially lower number of revolutions is required than in the push method. In any case, there must be sufficient friction between the inside of the pipe and the clamping device, for example the clamping disc, so that the pipe can rotate against the resistance of the bending tool.

However, it is also possible to leave the pipe and the rigidly connected parts of the device at rest and the bending jaw and rotate the rigidly connected parts about the axis of the pipe.

Subsequent bending of the protruding tubular end into a flange or flange then proceeds gradually around the periphery of the tubular piece during rotation of the tube. For this purpose it is advantageous

A rotatable bending jaw is used to engage the inner side of the tubular end in its home or park position. Its axial width should be at least slightly larger than the bent section of the tubular piece. This ensures that the bent section is lifted as a whole and that its direct form does not change.

Preferably, the bearing surface of the bending jaw at the pipe end should have the same radius as the inner side of the pipe, so that the bent pipe end section has a large surface washer. In principle, however, a cylindrical form of the base surface of the bending jaw with a slightly smaller radius than the inner side of the pipe is also possible.

Since the rotatable bending jaw can only bend a partial region of the tube circumference, the tube must be brought to a uniform slow rotation. When the tube is rotated, the bending jaw slowly rotates to the desired bending angle position. This method of the invention can therefore be expertly referred to as a rotary rotary bending method.

In a further preferred embodiment of the invention, a pressure can be applied in addition to the pipe bending point from the outside of the pipe, preferably by means of a molding disk or the like, wherein the tip of the molding disk cross-section ends at the point where In this way, the shape of the bending edge, i.e. either sharp or round, can be determined quite precisely. Otherwise, the cross-sectional shape of the forming disk is determined by the maximum bending angle of the formed profile.

Since a great force is exerted on the forming disc when bending, a good grip and placement of the forming disc is a prerequisite for achieving a clean bending edge. Advantageously, the forming disc and its attachment are connected to the fixed and non-rotating bending jaw and its drive device into a fixed unit, thereby substantially increasing the stability of the device.

With low demands on the shape accuracy of the flange or flange to be preformed, bending without the use of a forming disc is possible at a relatively small tube wall thickness. In this case, it is the arc of the tubular wall that provides sufficient support for bending. Sharp edges cannot be formed and the bending edge radius becomes increasingly larger as the thickness increases.

BRIEF DESCRIPTION OF THE DRAWINGS

The process according to the invention and the preferred embodiments of the device according to the invention are explained in more detail with reference to the drawings, in which:

Fig. 1 - Fig. 12 shows the operating sequence of the method according to the invention by means of successive working steps for fitting the conical flange at the end of the pipe, the parts of the apparatus shown schematically in side view serve only as an example for the machining effects thus obtained; 13 shows a schematic side view of a first embodiment of a device for carrying out the method according to the invention in a first working position; FIG. 14 a side view of a device corresponding to FIG. 13 in a second working position; 16 shows a schematic partial section along the line XVI-XVI in FIG. 13, FIG. 17 a schematic front view of the tensioning disk used in the apparatus of FIGS. 13 to 18, FIG. 18 a front view of the parts 17, 19 is a schematic side view of the clamping disk, tube and cup FIG. 20 shows a reduced side view of a portion of the components shown in FIG.

FIGS. 21 and 22 are axial sectional and schematic side views, respectively, of another embodiment of the clamping disc; FIGS. 23 and 24 are schematic side views of the tube, clamping disc, bending jaw and molding disc at different bending jaw positions; Figures 25 to 29 are schematic partial side views of the clamping disc and the bending jaw in various bending positions with molding discs having different cross sections, respectively without the molding disc; Figs. 30 to 31 partially exposed schematic oblique views of part of the device Fig. 32 is a partial oblique view corresponding to Fig. 30, without the tube and the molding disc, Figs. 33 to 35 of the illustration corresponding to Fig. 32, with the disc, the molding disc and the bending jaw in the parking or bending position, the bending jaw respectively. Fig. 36 is a schematic side view of the embodiment with two devices according to the invention operating simultaneously at both ends of the pipe.

DETAILED DESCRIPTION OF THE INVENTION

Giant. 1 to 12 show schematically the operating procedure of the method according to the invention at one end of the pipe 12. FIG. 1 shows a partial cross-section of a substantially untreated, unprocessed, tubular piece 10 of a tube 12 with a circular cross section in FIG. Giant. 2 shows the state of the tubular piece 10 for the first processing step. The tubular piece 10 is bent outwardly along a curved edge with a bending angle 14 of, for example, 150 ° against the axial direction 16 of the pipe 12.

Giant. 3 shows the state of the pipe 12 after the second bending step, in which the second pipe piece 18 following the first pipe piece 10 is bent outwards for example by a right angle against an axial direction 16 with a sharp edge with a bending angle 20. This results in a conical flange consisting of mutually connected tubular pieces 10 and 18, which is uniformly molded on the tube 12.

The following Figures 4 to 12 show schematically the operation of an apparatus for carrying out the method according to the invention. In the figures, the same reference numerals are used for the same components.

Giant. 4 shows the tube 12 in a not yet tensioned state near the clamping disc 22, which is in an unsecured parking condition, and which is fixedly mounted on the drive shaft 24, which forces the clamping disc 22 to rotate by force. The first bending jaw 26 for bending the first tubular piece 10 by 150 ° to a position corresponding to FIG. 2 is shown partially in the park position prior to the bending process in FIG. It should be noted that Figs. 1 to 3 are 180 ° mirrored relative to Figs. 4 to 12 on a plane perpendicular to the pipe axis 28.

The second bending jaw 30 is 180 ° rotated about the pipe axis 28 relative to the first bending jaw 26 also in its neutral position before the bending process and partially cut off. The second bending jaw 30 serves to deflect the second tubular piece 18 by 90 ° from the axial direction 16 to a position corresponding to FIG. 3.

Referring now to FIG. 4, the first molding disc 32 and the second molding disc 34 are also shown in their parking positions at a distance from the pipe 12. The first molding disc 32 has a cross-section with a rounded tip 36 whose sides 40 form an angle of 30 °. Rotated 180 ° with respect to the tube axis 28, a second molding disk 34 is arranged in its parking position at a distance from the tube 12, the cross section of which has a sharp edge of the tip 38 and whose sides form a right angle. The illustrated position of the individual parts of the device corresponds to the state at the beginning of the method.

-4GB 297829 B6

Giant. 5 shows a further operating state in which the clamping disk 22 has traveled into the tube 12 and in the direction of the arrows 44 has assumed its expansion position, stretching the tube 12 from its inner side. Together with the clamping disc 22, the bending jaws 26 and 30 have been driven into the tubular end, however, both of which are still in the park position with respect to their rotation for bending the tubular end. Also, the two mold disks 32 and 34 are still in the park position as in the situation of FIG. 4.

At the same time, the drive shaft 24 is rotated in the direction of the arrow 46 so that the clamping disk 22 rotates with the tube 12 while the bending jaws 26 and 30 as well as the forming disks 32 and 34 do not rotate about the tube axis 28. The frictional resistance between the cylindrical outer surface 48 of the clamping disk 22 and the inner surface of the tube 12 is so great that the clamping disk 22 is in its operating position of FIG. 5 such that the tube 12 also rotates due to the high resistance.

A further working step of the processing method is shown in Fig. 6, where the first molding disk 32 has moved in the direction of the arrow 50 along the feed axis 52 to its working position, where it firmly rests on the outside of the tube 12.

According to FIG. 7, the first bending jaw 26 is then rotated in the direction of arrow 54 in its parking position of FIG. 6 to its working position of FIG. 7 by an angle of 150 DEG about an axis running perpendicular to the drawing, the clamping disc 22 protruding over the tubular piece 10 about 150 ° around the first mold disc 32. Since at the same time the drive shaft 24 and the clamping disk 22 together with the interlocking tube 12 rotate about the pipe axis 28, after several revolutions of these components about the pipe axis 28, the pipe piece 10 is bent without breaking around the rounded edge with bending angle 14 out 150 °. By rotatably supporting the first molding disc 32, the frictional resistance with the tubular piece 10 occurring at the bending point is substantially reduced.

Subsequently, according to FIG. 8, the first molding disc 32 is returned along its displacement axis 52 in the direction of arrow 56 from its working position again to its parking position remote from the tube 12, and at the same time the first bending jaw 26 rotates back from its operating position in the direction of arrow 58. again to its parking position.

At the next working step of FIG. 9, the second molding disc 34 is moved along the displacement axis 60 in the sense of arrow 62 from the park position to the fixed stop position on the outside of the tube 12 and at the same time the first bending jaw 26 rotates back from its operating position. in the direction of arrow 58 again to its parking position.

At the next working step of FIG. 9, the second molding disc 34 is moved along the displacement axis 60 in the sense of arrow 62 from the park position to the fixed position operating position on the outside of the pipe 12. All these processes proceed while the drive shaft 24, the clamping disc 22 and the tube 12 rotate about the tube axis 28 and the first bending jaw 26 and the second bending jaw 30, as well as the two forming disks 32 and 34 are stationary.

Suitably, therefore, the rotating parts and the non-rotating parts are combined into a stable working unit. Naturally, the possibility of moving the individual parts from the parking position to the working position must be guaranteed inside the non-rotating working unit. On the other hand, it is naturally also possible to keep the working unit consisting of the drive shaft 24, the clamping disk 22 and the tube 12 at rest and the second working unit consisting of the bending jaws 26, 30, and the forming disks 32, 34 to rotate.

In the next working step of FIG. 10, the second bending jaw 30 is rotated in the sense of arrow 64 from its park position to the working position, thereby the second tubular piece 18 protruding over the clamping disk 22 with a sharp bent edge with a bending angle 20 corresponding to diameter. of the second molding disc 34, bent 90 ° outwards. The complete outward bending of the second tubular piece 18 of the tube 12 is achieved when the rotating parts perform a certain number of turns about the tube axis 28.

-5 CZ 297829 B6

In the next working step of FIG. 11, the second molding disc 34 returns along its feed axis 60 in the sense of arrow 66 to its parking position at a distance from the tube 12 and the second bending jaw 30 rotates back to its parking position.

This clears the way to return all the parts to the starting position shown in FIG. 4. Thus, at the end of the processing, all of the parts are again in the starting position of FIG. 4 as shown in FIG. flange with tubular pieces 10 and 18.

13 to 16 show schematically a preferred embodiment of an apparatus for carrying out the process according to the invention with all the essential parts according to the invention. For the sake of clarity, pieces are separated from the individual parts, for example from the tube 12, the clamping disk 22, the drive shaft 24 and the bending jaw 26. It should also be noted that only one bending jaw 26 and one molding disc are shown Of course, other bending jaws and molding discs may be arranged around the pipe axis 28 outside the drawing. However, they may be omitted as they function in the same way as the parts shown in Figures 13 to 16.

Since a separate working unit consisting of a bending jaw and a molding disc is used for each bent edge, it is an advantage that no work tools need to be changed for the individual work steps. Particularly in series production, it is important that the working units can be used one after the other without engaging each other.

Each working unit comprising a bending jaw 26 and a molding wheel 32 is mounted on a movable carriage 70, and a plurality of these carriages 70 can be radially arranged on the base plate 72. In this way, the individual working units can be easily adapted to the diameter of the pipe 12 to be processed. 70 can move along two parallel slide guides 71 in the sense of the double arrow 74 along a lead screw 78 rotated by the rotary drive 76.

Two parallel side plates 80 of FIG. 16 are arranged at a distance from each other on the carriage 70 and are fixedly connected to each other by means of intermediate plates 82. Between the two side plates 80 there is a wide sector plate 84 in the form of a circular sector on which the bending jaw 26 is fixed by means of screws 86 with a sliding fit on the inside of the side plates 80.

The sector plate 84, in its cross-sectional view, as shown in FIG. 13, forms an incomplete circular sector parallel to the side plates 80, whose central section opposite the arc 88 is absent, since the center of the circular sector must be dedicated to bending the tubular piece. The bending jaw 26 is fixed by means of screws 86 to a surface of a sector plate 84 corresponding to one of the flanges 92.

It should be noted that in Fig. 16, unlike Figures 13 to 15, only the parts of the device needed to rotate the bending jaw 26 are shown.

The guiding of the sector plate 84, with the necessary rotation, together with the bending jaw 26, is guided by guide rollers 94 which run in guide grooves 96 in the form of a circular arc in the side plates 80. The guide rollers 94 protrude on both sides from the sector board 84 and are guided in the guide In the cylindrical peripheral surface of the sector plate 84, corresponding to the circular arc 88 of the cross-section of the sector plate 84, a toothing 98 is provided that engages a drive pinion 102 driven by a rotary drive 100.

-6GB 297829 B6

Thus, the sector plate 84 may be rotated from the position corresponding to the parking position of the bending jaw 26 of Figs. 13 and 14 to the position of Fig. 15 corresponding to the working position of the bending jaw 26. The angle of rotation of the sector board 84 may be arbitrarily selected in the case of an angle between the two flanks of the cross-section of the first molding disc 32.

13 to 15, the first molding disc 32 is rotatably mounted about its central axis 105 in a forked bearing rack 104 which can be moved in the direction of the double arrow 50, 56 from its parking position of FIG. 14. A guide screw 106 driven by the drive motor 108 is disposed to displace the bearing rack 104. Importantly, the bearing rack 104 with the first flask 32 is rigid and high in the operating position of FIGS. 14 and 15. connected to the working unit by means of a bending jaw, a shaping disc and corresponding parts.

In the operating state of FIGS. 13 to 15, the clamping disk 22 is pushed into the end of the tube 12 by sliding the tube 12 while in the relaxed parking position described above. Subsequently, the clamping disk 22 is locked in its operating position as described below and now tensiones the tube 12 cylindrically from the inside out. In this case, a tubular piece 10 protrudes over the cylindrical outer surface of the clamping disc 22 and is to be bent by means of the subsequent bending process.

Before sliding the tube 12 onto the clamping disc 22, the working unit consisting of the bending jaw, the forming disc and the respective bearing and drive devices is adjusted by adjusting the slide 70 along the double arrow 74 relative to the fixed base plate 72 to match the actual diameter of the tube 12.

13 to 15 show only one such working unit. Other working units can be positioned on the base plate 72, with most of the double slide guides 71 radially directed from the pipe axis 28, so that they can subsequently be applied successively to the pipe 12 to transform the pipe piece 10, 18 into a complicated flange. To each slide 70 there is provided a rotary drive 76 with a lead screw 78, a threaded slider 110 moving along the lead screw 78 and a bracket 112 for connection to the slide 70, wherein the bracket 112 can be displaceable radially to the tube axis 28 72.

The design and operation of the first embodiment of the clamping disc 22 will be explained in more detail below with reference to FIGS. 17-20. Since the role of the clamping disc 22 is to prevent any shape changes of the inner side of the tube 12, it is important The cylindrical circumferential surface 116 on the side of the pipe 12. The illustrated preferred embodiment of the clamping disk 22 therefore has a division into a plurality of six sectors 118 in the illustrated embodiment, which are subsequently described by an extension end 120 of a draw bar 122 provided with an axial draw drive. 124, for example in the form of a hydraulic cylinder, from the inner parking position shown in the left half of FIG. 17a to FIG. 18, striking the inner side of the tube 12 into contact with the outer working position shown in the right half of FIG. 17 and FIG.

The number of sectors 118 is arbitrarily large. A plurality of sectors 118 have the advantage that the slots 126 between the sectors 118 formed by the expansion of the clamping disc 22 are smaller and the walls of the tube 12, although very thin, can bypass them without a shape change of the tube 12. in the form of a circular ring and ends inwardly from the pipe axis 28 in the inner surface 128 in the form of a cylindrical sector. The radial width of the sectors 118 may be chosen arbitrarily in order to adapt the diameter of the clamping disc 22 to the actual diameter of the pipe 12. This adjustment can be accomplished by simply replacing the sectors 118.

The inner surfaces 128 of the sectors 118 abut the cylindrical outer surfaces 130 of the clamping jaws 132 in the form of an annulus. The sectors 118 are secured to the clamping jaws 132 by radial screws 142. The clamping jaws 132 have an inclined inner face with respect to the pipe axis 28

-7 GB 297829 B6

134, which abuts the side surface 136 of the extension end 120 of the draw bar 122. In the illustrated embodiment, the extension end 120 has a hexagonal cross section so that one side surface 136 is provided for each of the six clamping jaws 132.

The main drive shaft 24 for rotating the clamping disk 22 and the tube 12 is axially drilled axially through the borehole of the drawbar 122. Under the action of the hydraulic cylinder of the drawbar 124, the drawbar 122 is moved from the parking position 138 shown in the lower half of FIG. 19. By this, the sectors 118 are moved from the parking position at a slight distance from the inner surface of the tube 12 shown in the left halves of FIGS. 17 and 18 to a working position with a pressure bearing against the inner surface of the tube 12. 17 and 18. This adjustment is mediated by a corresponding displacement of the clamping jaws 132.

The drive shaft 24 passes through a recess 144 in the base plate 72 of the entire apparatus, is rotatably mounted to the person skilled in the art and is rotated by a drive motor 146 with a hollow shaft drive device 148. The opposite end of the drive shaft 24 has a mushroom extension 150 with a planar face 152 on which the plain sliding surfaces 154 of the gripper jaws 134 are radially sliding. The sliding surfaces 156 of the gripper jaws 132 opposite the sliding surface 154 are sliding against fastened by bolts 160 to the mushroom extension 150. The bolts 160 extend through the widened holes 169 in the clamping jaws 132, which permit slight radial displacements of the clamping jaws 132.

The screws 160 are surrounded by spacers 162 which together with the holes 169 of the clamping jaws 132 guarantee linear radial guidance of the clamping jaws 132.

The hydraulic cylinder of the traction drive 124 for operating the traction rod 122 is axially supported on the hollow shaft drive assembly 148. The force of the hydraulic cylinder of the traction drive 124 alone, by itself, can be increased several times as desired by tapering the widening end 120 of the traction rod 122 relative to the pipe axis 28. This necessarily generates a great clamping force which generates a sufficient frictional engagement of the clamping disc 22 with the wall of the tube 12 to rotate the tube 12 against the resistance of the bending tool, the bending jaw 26 and the first forming disc 32. Of course, the chamfer of the widening end 120 may also be reversed, i. in FIG. 19, the descent to the right may occur when an otherwise operating lever is operated.

The return of the clamping jaws 132 when the clamping disc 22 is released back into the park position can be effected in a simple manner by means of springs (not shown) which are recessed in the individual clamping jaws 132 or also by an endless tension spring, not shown. flush into a groove (not shown).

Alternatively, the drive shaft 24 in the embodiment shown in FIG. 20 may also be mounted with a spherical collar 164, the outer side of which is also provided with a toothing 166. In this case, the drive motor 146 is located next to the spherical collar 164. 170 engages in the toothing of the spherical ring 164 and serves to drive the drive shaft 24. Naturally, other kinds of bearings obvious to one skilled in the art can also be used.

Another preferred embodiment of the clamping disc 22 and its drive are shown in Figures 21 and 22. In this embodiment, the clamping disc 22 has a circumferential clamping ring 174, divided by a sloping groove 172, with a cylindrical peripheral surface 116 and a conical inner surface 176. the inner surface 176 abuts with the same conicity the outer surface 178 of the clamping plate 180, which is fastened to the widened end 186 of the draw bar 122 by means of screws 182 and nuts 184.

By moving the tension rod 122 in the sense of the double arrow 188 between the relaxed parking position shown in the upper halves of FIG. 21a and FIG. 22 and the tensioned operating position shown in FIG.

In the lower halves of FIG. 21a and FIG. 22, the clamping ring 174 can be tensioned or loosened with any great force. The groove extending in the clamping ring 174 could itself be arranged in the axial direction parallel to the pipe axis 28. However, the inclined configuration of the groove 172 prevents the opening of the gap from opening causing a gap in the tension of the tube wall and hence deformation at this point.

In this case, the returning of the clamping ring 174 upon release takes place by the self-resilient action of the ring. If necessary, this spring action is amplified by a peripheral endless tension spring (not shown) in the groove of the clamping ring 174.

It will be appreciated that the thickness of the sheet metal of the tube 12, the desired flange shape, or material exchange does not affect the clamping disk 22. The tubular pieces 10, 18 are always pushed over the clamping disk 22 to the extent that sufficient material is available when molding the desired flange.

23 to 35 show preferred embodiments of the bending jaws 26 and the first forming disks 32 together with the section of the deformed tube 12 and a portion of the expanded clamping disk 22.

Figures 23 and 24 show a first embodiment, wherein the sliding first molding disc 32, in the operating position as described above, is pressed against the outside of the pipe 12. The bending jaw 26, rotatable according to the above described method, rests in its parking position on the inner side of the tubular piece 10 protruding over the clamping disc 22 and to be bent, the wall of the pipe 12 being clamped and held between the clamping disc 22 and the first molding disc 32. The cross-sectional tip 36 of the first molding disc 32 terminates pipe piece 10 bent. The shape of the first molding disc 32 can determine the shape of the bending edge at the end of the tube 12.

The pivot bending jaw 26 abuts the inner side of the tubular piece 10 in its parking position of FIG. 23. Its axial width should be at least slightly greater than the axial length of the tubular piece 10. This ensures that the tubular piece 10 is lifted as a whole. and its direct form will not change. Likewise, the cylindrical bearing surface 190 of the bending jaw 26 at the end of the tube 12 should have the same radius as the inner side of the tube 12, whereby the bent tube piece 10 has a large surface stop.

Since the bending jaw 26 can bend only a portion of the circumference of the tube 12 at a given time, the tube 12 must be brought to a uniform slow rotation. When the tube 12 is rotated, the bending jaw 26 is slowly rotated to the desired bending angle position of FIG. 24. In this operating position, the bending jaw 26 remains until the end of the last complete rotation of the tube 12 about the tube axis 28, thereby bending the tubular to usu 10 .

In order for the tube 12 to be pulled away from the clamping disc 22 after the flange or rim has been formed, the first forming disc 32 with its bearing stand 104 has to be moved to its parking position at a sufficient distance from the tube 12. For the next bending process is set to a different bending angle.

For comfortable insertion of the clamping disc 22 into the pipe end 10, the inlet side of the cylindrical outer surface 48 may have a tapered bevel 192.

25 to 28 show various embodiments of the molding disc 32 or 34 with a slender tip 36 or a rectangular tip 38. The tip 36 serves to bend the tubular piece 10 by 150 °, while the tips 38 serve to bend the tubular piece 10 by 90 ° .

FIG. 29 schematically illustrates how, with low demands on shape accuracy, a flanged flange or rim can be bent entirely without the forming disc with only the clamping disc 22 and the bending jaw 26.

-9EN 297829 B6

Giant. 30 and 31 illustrate the formation of a bending jaw 26 with an almost half-cylindrical bearing surface 190 in the parking position of FIG. 30 and the working position of FIG. 31.

Giant. 32 shows an enlarged representation of a somewhat differently formed bending jaw 26 with a flat cylindrical bearing surface 190, which is fixed by means of screws 86 to only the partially rotatable sector plate 84. The bearing surface 190 bears with full frictional force on the inner wall of the tube (not shown).

The following figures illustrate some preferred embodiments of the bending jaw 26 similar to that of Figure 32, but with reduced friction between the bearing surface 190 and the inner wall of the pipe 12. It is ideal for itself if the working radius of the bearing surface 190 of the bending jaw 26 corresponds to the inner diameter of the pipe However, without the engraving disadvantages, however, the radius of the bearing surface 190 may also be smaller than the inner radius of the tube 12. It is thus possible to machine different tube diameters 12 alternately with the same bending jaw 26.

At the point of the main friction in the center of the bearing surface 190, in order to substantially reduce the friction and abrasion, a rolling roller support 194 can be inserted into the body of the bending jaw 26 whose axis of rotation, shaft 196 extends parallel to the bearing surface 190 and whose peripheral surface 198 slightly protrudes The bent tubular piece 10 then rests against the circumferential surface 198 of the support roller 194 in this region without friction.

The bending jaws 26 can be further improved by inserting the entire chain of support rollers 194 into the abutment surface 190 of FIG. 34, in the same manner as one support roller 194. In the illustrated embodiment of FIG. 34, five such support rollers 194 are disposed in one chain. The remaining parts of the bearing surface 190 between the support rollers 194 prevent the wall of the tube 12 from falling between the support rollers 194, which could lead to waves and elongations.

Minimal friction between the bending jaw 26 and the inner wall of the tube 12 is achieved when the bending jaw 26 of Figure 35 is formed as a complete cylinder with a cylindrical bearing surface 190, wherein the entire cylindrical bending jaw 26 is rotatably supported on the sector plate 84 Thus, although the lowest friction is achieved, there is usually not enough space for a larger diameter of the cylindrical bending jaw 26, so that the disadvantages associated with wave formation and elongation have to be taken into account. These drawbacks are smaller with larger wall thicknesses of the pipes 12 than with sheet thicknesses from 1.5 mm, such "bending rollers" can be used instead of bending jaws 26.

The device according to the invention for carrying out the bending method according to the invention can be used with both horizontal and vertical tube axis 28, the first embodiment being suitable for straight tubes 12 and the second embodiment for short tubular sections.

For the rational manufacture of straight tubes 12 with flanges fitted at both ends, two circularly rotatable bending devices 204 of the type of the present invention are disposed on the common rail system 202, traveling along the system in the direction of the double arrow 206 so that the two clamping Each device 204 can be moved on the rail system 202 by its own driven lead screw forming the drive 208.

To insert the tube 12, the device 204 is spaced apart until the distance between the clamping disks 22 is adapted to the length of the pipe 12. Then the device 204 approaches and the clamping disks 22 travel into the pipe ends to a stop that is set to the length of processing of the pipe ends. The two tensioning disks 22 are tensioned into the working position and the processing is simultaneously carried out at both ends. In order to remove the tube 12, the device 204 has to be moved apart again.

-10GB 297829 B6

PATENT CLAIMS

Claims (21)

A method for uniformly flanging a flange or rim at the end of a sheet metal tube, characterized in that the tube is extensively flattened and clamped near its end on its inner side, and wherein a pipe piece is allowed to protrude over the flat and clamped pipe section the axial partial section of the protruding tubular piece is bent by flat pressure against the circumferential section of its inner surface up to the desired bending angle outward from the pipe axis and that the relative rotation of the tube with respect to the circumferential section in which the bending occurs is the entire tubular piece; its partial section is given the desired bending angle. Method according to claim 1, characterized in that the bending of the outside of the pipe at a location within the peripheral section in which the bending takes place is prevented by a pressure action on the bending point from the outside of the pipe. Method according to claim 2, characterized in that the pressure action on the bending point takes place with slight friction on the pipe rotating relative thereto. Method according to one of the preceding claims, characterized in that the method of molding a multiple-bent flange is performed several times in succession. Device for carrying out the method according to one of the preceding claims, characterized in that it comprises a clamping disk (22) with a cylindrical outer surface (48) for insertion inside the tube (12) which is adjustable between parking position at a slight distance from the inner surface of the tube (12) and a spaced position with abutment on the inner surface with friction, according to the drive disc (22), a fixed drive shaft (24), a drive motor (146) for rotating the drive shaft (24) against high resistance and bending jaw (26) , 30) with an at least partially cylindrical bearing surface (190) for abutting the tubular piece (10, 18) which are rotatable between a parking position with abutment on the inside of the bent tubular piece (10, 18) and an operating position corresponding to the finished bent tubular piece (10, 18), wherein the cylindrical diameter of the bearing surface (190) is less than or equal to the diameter of the bent tubular piece (10, 18) ) and the cylindrical height of the bearing surface (190) is greater than the length of the tubular piece (10, 18). The apparatus of claim 5, further comprising forming discs (32, 34) imaginable between a parking position spaced from the pipe (12) and an operating position abutting the outside of the pipe (12) at the bent edge of the bent pipe piece (10, 18) and which are rotatably mounted in a bearing rack (104) which is rigidly connected to the bending jaws (26, 30) relative to the pipe axis (28). Device according to claim 5 or 6, characterized in that the clamping disc (22) consists of a number of sectors (118) which can be adjusted between the parking position and the span position of the clamping disc (22) by means of a span device. Apparatus according to claim 7, characterized in that the span device comprises an expanding end (120) on the pull rod (122), which cooperates with the lateral surfaces (136) with inclined relative to the pipe axis (28). ) at the inner end of the clamping jaw (132) interacting with the sectors (118), the pull rod (122) being coupled to the pull drive (124). The apparatus of claim 8, further comprising a resilient return device for the sectors (118) from the working position to the parking position. -11 CZ 297829 B6 Device according to claim 5 or 6, characterized in that the clamping disk (22) consists of an externally cylindrical and internally tapered clamping ring (174) and a tapered clamping plate (180) on the conical inner surface (176) of the clamping ring (174). ) with a conical outer surface, which is located on the traction rod (122) with the traction drive (124). Device according to claim 10, characterized in that the groove (172) of the clamping ring (174) extends obliquely to the longitudinal axis of the clamping ring (174). Device according to one of Claims 5 to 11, characterized in that a support roller (194) is inserted into the recess of the bearing surface (190) of the bending jaw (26) at one or more points of the bearing surface (190). The surface (190) protrudes slightly and is rotatably supported on the shaft (196) parallel to the cylindrical axis of the bearing surface (190). Device according to claim 12, characterized in that a plurality of parallel support rollers (194) are spaced apart from one another in the recesses of the bearing surface (190) of the bending jaw (26). Apparatus according to one of Claims 5 to 11, characterized in that the bending jaw (26) is designed as a complete cylinder bending roller, which is rotatably mounted on its rotary shaft (200) passing through the cylindrical axis, the rotary bearing is rotatable with the bending pulley between the parking position and the working position. Apparatus according to one of Claims 6 to 14, characterized in that the molding disc (32, 34) has a rounded or sharp-edged tip (36, 38) on its circumference, which passes into the boundary planar sides (40, 42). which form an angle to each other determined by the desired flange bending angle (14, 20). Apparatus according to one of Claims 6 to 15, characterized in that the rotatable bending jaw (26) and the molding disc (32) with associated bearing and drive devices are combined into a stable working unit which is formed with a pipe ( 12) and a clamping disc (22) including bearing and drive devices rotatable about a pipe axis (28). Apparatus according to claim 16, characterized in that a plurality of working units are distributed around the circumference of the tube (12), which serve to perform special bending procedures to form a multi-bent flange. Apparatus according to claim 17, characterized in that the working units are disposed on the movable carriage (70) to adapt to the instantaneous diameter of the pipe (12). Device according to one of Claims 16 to 18, characterized in that each working unit comprises two side plates (80) which are fixedly connected to one another by means of intermediate plates (82) at opposite ends, such that they interconnect between the side plates (80). a wide sector plate (84) extends on both sides facing the side plates (80) of which a plurality of guide rollers (94) are rotatably mounted which run in guide grooves (96) in the form of a circular arc on the inside of each side plate (80) ) and that the sector plate (84) carries the bending jaw (26) of the working unit. Device according to claim 19, characterized in that the sector plate (84) forms an incomplete circular sector in cross-section parallel to the side plates (80), whose central section opposite the circular arc (88) is absent, the flanges (90, 92) following the circular arc (88) intersect off the center of the circular arc (88) and that a bending jaw (26) is fastened to the area of the sector plate (84) corresponding to one of the flanges (92). -12GB 297829 B6 Apparatus according to claim 20, characterized in that a toothing is provided on the cylindrical surface of the sector plate (84) corresponding to the circular arc (88), which engages a drive pinion (102) actuated by a rotary drive (100).